Touch sensor devices (also commonly called touch pads or touch screens) are widely used in a variety of electronic systems. A touch sensor device is typically a sensitive surface that uses capacitive, resistive, inductive, optical, acoustic or other technology to determine the presence, location and or motion of one or more fingers, styli, and/or other objects. The touch sensor device, together with a finger or other object provides an input to the electronic system. For example, touch sensor devices are used as input devices for computers, such as notebook computers.
In various embodiments, a touch sensor device typically includes an array of sensor electrodes configured to sense an input object in a sensing region of the device. To operate the sensor electrodes, each sensor electrode in the array is driven by driver circuitry, such as a buffer amplifier, that draws power from a power source. Driving the array of sensor electrodes in such a manner imposes a power consumption burden on the touch sensor device. Such a power consumption burden may be disadvantageous, especially when the touch sensor device is a device having a limited power supply. Further, the size of the driver circuitry is based on the amount of charge needed to drive the array of sensor electrodes, such that the larger the amount of charged needed the larger the size of the driver circuitry.
Therefore, there is a need for an improved input device, processing system, and method for a more efficient mechanism to drive sensor electrodes.